Allow reclassifications (eg older, slow BC to BB)

[yemo]

In the succession game with France, I have the problem that two BCs only make 23knots.

This is now too slow for scouting/cruiser engagements, but still fast enough to trail the battleline.

So I would like to put them at the end of the battleline, where they would be of some use, and keep them away from cruiser work.

Just unlock the dropdown ship classification for refits and when saving, check whether that classification works out.

edit: Only check the classification if it was changed, so it can not make a design illegal for a paint job.

[tbr]

I do already get checks of "old slow" BC's upon rebuild design where the game asks me whether I want to classify them as BB's...

This might be because I usually use pretty well armored BC's though...